Question

How would you prove that blue copper sulphate crystals contain water of crystallisation ?

Answer 1

When copper sulphate (blue vitriol ,CuSO4.5H2O) is heated then its blue colour fades away and it turns from Blue to White and becomes anhydrous copper sulphate (CuSO4) this happens because copper sulphate loses its water of crystallization.
In this way we can show that copper sulphate contains water of crystallization.